Intercommunicating system



April 5, 1932. c. E. LoMAx ET A1.

INTERCOHMUNICATING SYSTEM Filed may 12. i930 Ima-52m' t. SE

al Q NNW.

H .mi

Clarin/:E E. Lamas:

Jahn Unas [i la?.

A Patented Apr. 5, 1932 I y .QF :omtrvmnxLAND-JQHN YOSSM.; sIGNoRsg BYMEsNE IASSIGNMENTSQ'TO Asso clgmnnfmm oF "cnlcAG Emmons;` ACQRRQBMMON 0E LDELAW im# mi stem When the ringer 19 is actuated, the attendant at station N0. 1 answers the call by moving the station selecting arm 14 to its trunk contact 5 and removes the receiver. A circuit is now completed from ground supplied through the transmitter 10, the receiver 11, switchhook springs 13, the station selecting armll, its trunk contact 5, and over the previously-traced circuit through the relay A to the negative pole of the battery. Consequently, the relay A energizes and, at its upper contacts, completes a direct-current bridge across the trunk to cut ofi' the ringing current and provide answering supervision at the main exchange. The subscriber at station N 0. 1 can now converse with the calling subscriber and determinesy the number of the station desired. It will be assumed that sta tion No. 2 is desired. The attendant at sta- `tacts, places a shunt about the ringer 19 in multiple with the upper contacts of relay A, so that the relay A may be deenergized without effect so taras the condition of the trunk is concerned. The attendant at station No. lk

now replaces his receiver v11, thereby openingthe traced circuit through the relay A, which restores, and at its lower contact sets, completes a holding circuit for the relay B and an energizing circuit for the hold lamp L. The hold lamp glows, to notify the attendant at station No. 1 that the trunk is being held, and that the key 50 may be restored and the party wanted called over the intercommunicating system in the usual manner. The

party at station No.v 3, upon hearing his station signal 35, before answering moves his station selecting arm to the answering position ANS.

The party at station No. 3, uponibeing advised that he is wanted on the trunk,` simply moves his station selecting wiper34 to the trunk contact 5, and in so doing, completes the previouslytraced circuit through the relay A. Consequently, this relay again energizes and, at its lower contacts, opens the holding circuit of relay Band trunk hold lamp signal L. The extinguishing-of the hold lamp indicates to the attendant at station No. 1 that the station wanted has beeny connected with the trunk. Then the party at station No. 3 replaces his receiver, the relay A restores and removes the shunt from across the trunk, thereby giving disconnect supervision to the operator at the outside exchange. Thile only one trunk connection has been shown, obviously, one or more trunks may be addedl it required.

If the trunk terminates in an automatic exchange, those subscribers who areA to be permitted to make trunk calls are provided with impulse devices connected as illustrated in Fig. 2.

Under these circumstances, when a subscriber wishes to make a trunk call, he places his station selecting wiper on the trunk contact and proceeds to dial the called number of the outsideexchange subscriber. The A relay responds and at its upper springs repeats the impulses to the automatic switches of the outside exchange.

From the foregoing, it will be appreciated that applicant has provided a very simple and practical intel-communicating system which may'have trunk connections with either or` both manual and automatic exchanges.

vhat is claimed is:

1. In a telephone system a trunk line extending from one exchange to the stations of an intercommunicating system, a signal for said trunk vlocated in the vicinity of said stations and operable from the exchange to notify the parties at the stations that a connection with one of them is desired, a relay having contacts for placing a shunt about the signal to stop its operation and to give answering supervision at the exchange end of the trunk, and means at said stations for` causing the operation of said relay incidental to the removal of the receiver at any station.

2. In a telephone system a trunk line extending from` one exchange to the respective stations of lan,intercommunicating system, a signal for said trunk located in the vicinity otsaid stations and operable from the exchange to notify the parties at the intercommunicating stations that a connection with one of them is desired, a relay for placing a shunt about the signal to stop its operation and togive answering supervision at the exchange end of the trunk, means at said stations for causing the operation of said relay incidental to the removal of the receiver at anystation, a. second relay for vplacing a shunt about said signal, a second signal under control of said relays, means under the control of one of said stations which has answered an incoming call for causing the energization of the second relay to thereby hold the trunk independently of the first relay, a circuit for said second signal completed by said first relay consequent to the replacement of the receiver to notify the party at the answering station that the trunk is being held. and an operating circuit for thevtirst relay completed by the connection of any station with the trunk to cause the second signal to be deenergized to notify the first answering party that a second station has connected with the trunk.

3.y In combination with an intercommuni'- eating system in which each station is provided with a station selector and associated contacts for connecting with any other station of the system. and wherein a push button at the calling station may then be operated to signal the selected called station; a

fill

bil

tid

trank line extending from an outside exchange having an inductively connected extension with branches thereof terminating in the respective stations of the intercommunieating system in the same manner as do the lines of the other stations of the system.

i. In combination with an intercommunieatin@ system in which each station is provided with a station selector and associated contacts for connecting with any other station oi'l the system, and wherein a push button at the alling station may then be operated to signal the selected called station; a trunk line extending from an outside exchange and having branches terminating in the respect-ive stations of the intercommun'leating system iu the same respective relation thereto as do the other lines of the respective stations, and apparatus associated with thc trunk under control of the push buttons ol said stations to modify the condition of the trunk to signal an operator of the outside exchange when a connection with an outside exchange .subscriber is desired.

ln combination with a telephone system wherein all switching necessary to the establislnnent of local talking connections is accomplished at the substations, a trunk line extending from a distant exchange having branch connections terminating in the switching apparatuses of the stations of Ysuch system, and a relay under common control of the switching apparatus of all stations employed by them in answering calls extended over the trunk as well as in establishing trunk connections with the distant exchange.

b. In a telephone system, a trunk line extending Vfrom a main exchange and terminating in a branch exchange, a repeating coil, a winding of said repeating coil, a ringer, a condenser and a second winding of said repeating coil in a series bridge across said trunk line at the branch exchange, another winding of said repeating coil in available talking relation to any station of the system,

and means for shunting the ringer and condenser out of the bridge across said trunk when the lsame is taken for use by a subscriber at the branch exchange.

7. In a telephone system, a trunk line, a `signal in a permanent bridge across said trunk line, a plurality of stations associated `with said trunk, means available to any station of said system for placing a shunt across said signal to stop or prevent the operation oit said signal, and means operable at one of said stations for rendering lsaid signal again operative after the same has been rendered inoperative by another of said stations.

8. In an 'intercommunicating wherein the subscribers themselves perform all switching operations at their stations which are necessary to the completion of telephonic connections between said stations, a trunk line having one end thereof terminatsystem A ing in a main exchange and the other end having inductively connected branches terminatlng at the respective stations of the intercommunicating system, and circuits and apparatus enabling any station to answer or establish trunk connections throu l1 the medium of the inductive connection y the same procedure as followed in establishing interstation connections.

9. In combination with an intercommunicating system, a trunk to an outside exchange, and a relay in said trunk operable from a station of the intercommunicating system to signal an operator in case the trunk is connected with a manual exchange, and means also associated with said station for operating said relay to control automatic switches in case the trunk is connected with an automatic exchange.

In witness whereof I hereunto subscribe my name this 8th day of May, A. D. 1930.

CLARENCE E. LOMAX.

In witness whereof I hereunto subscribe my name this 8th day of May, A. D. 1930.

JOHN H. VOSS. 

